Scoville heat scale

From Cookipedia

The Scoville scale is a measurement of the spicy heat (or piquance) of a chili pepper. The number of Scoville heat units (SHU) indicates the amount of capsaicin present. Capsaicin is the nerve stimulant that gives chillies their hot 'taste'. A chilli with an SCU of 200,000 indicates that its extract must be diluted over 200,000 times before the capsaicin presence is undetectable.

The scale is named after its creator, American pharmacist Wilbur Scoville. His method was devised in 1912.